Power-transmission device.



No. 844,415. PATENTED FEB. 19, 1 07.

W. T. SEARS 7 (POWER TRANSMISSIQN DEVICE.

APPLICATION FILED OCTA. 1906'.

Witnesses: 4 1 4 I I 4 4 Inventor i BL W Attorney WILLARD THOMAS SEARS, or PHILADELPHIA, PENNSYLVANIA, ASSIGNOR PATENT FFIC.

, TO NILES-BEMENT-POND COMPANY, JERSEY CITY, NEW JERSEY.

POWER-TRANSMISSION DEVICE.

To aZZ whom it may concern:

Be it known that I, WILLARD THOMAS SEARS, a citizen of the United States, residing at Philadelphia, Philadelphia county,

Pennsylvania, have invented certain new and useful Improvements in Power-Trans.

mission Devices, of which the following is a specification.

This invention pertains to apparatus for the transmission of power, in which are involved relatively shifting toothed members for changing the rate of motion or the direction of motion or the condition from rest to and relates to im proved means for guarding a ainst first, the. difficulties of intermeshing t e teeth when motion, and vice versa,

, teeth do not ha pen to match tooth-spaces;

second, the lia ility of the transmission of heavy. work through teeth but partially eragaged, and, third, the labor of shifting teeth ,into engagement while they are under the strain of heavy duty. q 4

The invention will be readily understood from the followingdescription', taken in connection withthe accompanying drawings, in

which- Figure 1 is a front elevation of an apparatus embodying my invention, and Fig. 2 is a gear 'on the a side elevation of the portion of the drivingpulley in conjunction withthe auxiliary friction driving-arm.

Inthe drawings, 1 indicates housing parts;

the driving-shaftf 3, the driven shaft; 4, fast on the driven shaft; 5, a second but larger gear fast on the driven shaft; 6, apair of gears fast with each other and splined the pair of splined-gears and adapted to slide tion 11.

them so that its component gears may mesh with either of the mating gears, respectively,

on the driving-shaft; 8, a friction-clutch pulley, (conventionally shown',) which may be of any desired or suitable ordinary construction; 9, an endwise-movable bar to serve in engaging and disengaging the clutch; 10, an arm fast on the driving-shaft in position to have its outer end sweep around within the rim of the pulley of the friction-clutch; 11, an inward projection, of which there may be a plurality, inwardly from the rim of the ,pulley, and 12 a'yielding friction member on the outer end of the arm the form of a spring-pad to yieldingly engage the projectation'to the driving-shaft.

driving-shaft; 7, a shifter engaging- Patented Feb. 19, 1907.

The length of the arm should be such that, assuming the driving-shaft to be at rest, the pulley-rim will pass the end of the arm idly or with'clearance until the projection 11 reaches the end of the arm, at which time the rejection frictionally engages the arm and thus giving ro-. The spring-pad is merely an expedient for providing a reasonable de ree of elasticity at the. points of frictiona contact; In the illustrations the projection 11 is inward from the pulleyrim to engage theouter extremity of the arm ;.butit is manifest that such relative poightly drags the arm with it,

sition of the parts is not essential. to the aot complishment of the desired result, which is that the driving member (represented in the illustrations by'the friction-clutch pulley) shall be normally free of the driving-shaft until the rotation of the driving member brings some part upon it into, frictional engagement with some art carried by the ;driving-shaft.

'Now, to fol ow up the. ultimate result of this intermittent friction'driving device, assume the friction -clutch released and the pulley.

thereof turning loosely-on the driving-shaft, which latter, together with its gears 6, is consequently at rest. If an attempt be made to shift the gears 6 into en agement with one of the matin gears and-i that attempt result in failure y reason of tooth ends clashing with tooth ends, as is quite apt to occur,

the moving projection 1 1 will soon engage the end of the arm and turn the driving-shaft and its gearssufliciently to permit teeth to enter toothspaces, andas soon as this. is done the weak driving power exerted upon the arm will be insufiicient to impart motion to the driven shaft, the consequence being that the rojection on the pulley slips past the end 0 the arm and the sliding gear comes torest with its teeth initially enga ed with the teeth of the mating gear. Un er these conditions and while there is no strain on the teeth the gear may be slid into complete engagement; Simple and efiicient means is thus provided for permitting the certain and safe and easy engagement of the teeth, it being understood that the friction-clutch will be engaged and'the full power thrown on only after the complete enga ement has been effected. The defects an difficulties which have been referred to as incident to ordinary constructions of transmission devices employing shiftabl'e teeth are well IBC-l ognized as generally existing in all manner of transmission devices in which are involveda.

air of toothed members to be throwninto Y and out of engagement with each other, and

the present invention is applicable to most any transmission" system employing such system ottoothed members. The shifter and.

the clutclyoperating bar may be actuate'd'by any usual or suitable means, so as to bring about in the usual manner the locking of the clutch-pulleyto and its unlocking from its shaft.

' I claimv j 1. A transmission device comprising a pair.

of toothed members, means for shifting one of said members into andout of engagement with the other, a rotary dri-vin transmitting motion to the toothed 'm'embers, means for connecting and, disconnecting said rotary transmitting part to and from one of the toothed members, and a periodicallyacting friction device between the. rotary for-locking the part for transmittingpart and the toothed member to which it is connected, combined substantially as set forth.v

25A transmission device comprising a driving-shaft, ,a-rotary driving part loose combined substantially as set forth.

3. A transmission device comprising a driving-shaft, a pulley loose thereon, a clutch u-lley to the shaft, a projec .tion carriedbyt e'pul-ley; and an arm carried by the driving-shaft and adapted: to be period ieal l y' engaged by the projection of' thepu'lley,

combined substantially as set forth.

I .ILLABD THOMAS'SEARS, f Witnesses: J

ABCHIBALD M. OBRrEm. SAMUEL O. KANE. 

